The present invention is generally related to guided-wave devices and, more particularly, high index contrast waveguides and methods for preparing high index contrast waveguides.
In general, waveguides are transmission paths adapted to direct the propagation of electromagnetic waves (e.g., light) in a longitudinal direction, while confining those electromagnetic waves within a certain cross section. A waveguide is defined, in its simplest form, as a set of two or more materials consisting of a region of high refractive index (referred to hereafter as the core region) surrounded by a region or regions of lower refractive index (referred to hereafter as the cladding region(s)).
In this regard, the selection of waveguide core and cladding materials is limited to those materials where the refractive index of the waveguide cladding material exhibits a lower refractive index than the waveguide core material. Proper selection of materials can increase the contrast in the refractive index between the waveguide core and the waveguide cladding. Two key advantages to a high index contrast waveguide technology include decreased bending loss along bent waveguide paths and reduced cross-talk between adjacent waveguides. Lower bending loss allows for more efficient optical power budgets, while reduced crosstalk enables higher interconnect density and reduced optical power splitter dimensions.
Thus, a heretofore unaddressed need exists in industries employing optical waveguide technology to address the aforementioned deficiencies and/or inadequacies.
Briefly described, the present invention provides for waveguides. A representative waveguide includes a waveguide core having an air-gap cladding layer engaging a portion of the waveguide core.
The present invention also involves a method of fabricating waveguides. A representative method includes: providing a substrate having a lower cladding layer disposed on the substrate; disposing a waveguide core on a portion of the lower cladding layer; disposing a sacrificial layer onto at least one portion of the lower cladding layer and the waveguide core; disposing an overcoat layer onto the lower cladding layer and the sacrificial layer; and removing the sacrificial layer to define an air-gap cladding layer within the overcoat polymer layer and engaging a portion of the waveguide core.
Other systems, methods, features, and advantages of the present invention will be or become apparent to one with skill in the art upon examination of the following drawings and detailed description. It is intended that all such additional systems, methods, features, and advantages be included within this description, be within the scope of the present invention, and be protected by the accompanying claims.